WO2005119194A1

WO2005119194A1 - Pressure sensor module and pressure detecting device

Info

Publication number: WO2005119194A1
Application number: PCT/JP2005/010022
Authority: WO
Inventors: Kenji Nagasawa; Ayumu Sakamoto; Takahiro Shimada
Original assignee: Nagano Keiki Co., Ltd.
Priority date: 2004-06-03
Filing date: 2005-06-01
Publication date: 2005-12-15
Also published as: JPWO2005119194A1; EP1754963A4; EP1754963B1; KR100970038B1; EP1754963A1; US7367233B2; TW200604504A; TWI359263B; KR20070034478A; US20070227254A1; JP4065894B2

Abstract

A pressure sensor module (2), wherein a holding space (34) is formed between a diaphragm (22) and a thin film layer (31), and a vent hole (321) communicating with the exterior of a first case is provided in the holding space (34). In the above pressure sensor module, even when a corrosive gas or chemical solution is used as a fluid to be de measured and a corrosive gas component originated from the fluid to be de measured permeates into the holding space (34), the permeated corrosive gas component can be discharged to the outside of the case through the vent hole (321). As a result, the corrosion of the diaphragm (22) by the fluid to be de measured can be prevented, which results in the achievement of a prolonged life of the pressure sensor module (2).

Description

Specification

Pressure sensor module and pressure detection device

Technical field

The present invention relates to a pressure sensor module that detects the pressure of a fluid to be detected, and a pressure detection device.

Background art

[0002] Conventionally, there are pressure transmitters and pressure measuring devices used for piping of highly corrosive gases and chemicals. Such pressure transmitters and pressure measuring devices are provided with a pressure sensor module that comes into contact with highly corrosive gas or chemical solution and detects the pressure (for example, see Patent Documents 1 and 2).

[0003] In the diaphragm pressure sensor described in Patent Document 1, a pressure introduction member made of PFA (PerFluoroAlkoxylalkane) is fitted on the opening side. A pressure receiving pedestal made of PFA is welded to this pressure introducing member, and a diaphragm is bonded to a surface on the inner side of the pressure receiving pedestal. Further, a pressure sensor unit is provided on the inner surface of the diaphragm, and the displacement of the diaphragm due to the pressure of the gas to be detected or the chemical solution is converted into a resistance change and extracted as an electric signal. Here, the surface of this diaphragm is protected by PFA resin to prevent it from being corroded by highly corrosive gas or chemical solution.

[0004] In the pressure sensor module described in Patent Document 2, a flexible film is provided on a lip of a cavity, and a pressure sensor is provided on a top portion of the flexible film. The flexible membrane is displaced, and the pressure of the fluid to be detected is detected by detecting the amount of displacement with a pressure sensor. The flexible film is formed of, for example, Teflon (registered trademark of "I", "I", "Dupont", "Dou", "Numur", and "Compa-I"), and the upper surface of the flexible film has grooves, Alternatively, a channel pattern is formed and the pinhole passage is left. In addition, a passage is formed which escapes from the side of the surface of the flexible membrane opposite to the surface on the pressure sensor side into the cavity center region.

Patent Document 1: Japanese Patent No. 3410711 (Page 2, FIG. 1)

Patent Document 2: Patent No. 3323513 (Page 6, FIGS. 4 to 15) Disclosure of the invention

Problems to be solved by the invention

[0006] Meanwhile, in the diaphragm pressure sensor described in Patent Document 1, the pressure receiving pedestal of the PFA and the diaphragm of the pressure sensor are directly adhered by an adhesive. However, in such a configuration, the corrosive gas component of the fluid to be detected may permeate to the diaphragm side. In such a case, the diaphragm is corroded, or the pressure receiving base bonded to the diaphragm is peeled off. Therefore, the durability of the pressure sensor is limited, and it is not suitable for long-time use.

[0007] Furthermore, the pressure sensor module described in Patent Document 2 uses a flexible membrane made of thin Teflon (registered trademark of "I'I'Dubon" Dou Numour and "Kampa-I") as the pressure sensor. This is a pressed configuration. However, in such a configuration, the corrosive gas component of the fluid to be detected may permeate in the same manner as in Patent Document 1 described above. In particular, when corrosive gas components of the fluid to be detected permeate from the flexible membrane due to prolonged use, etc., such permeated gas components corrode the pressure sensor and cause damage to the pressure sensor. May be

[0008] It is an object of the present invention to provide a long-life pressure sensor module and a pressure detection device that can maintain measurement accuracy even when used for a long time.

Means for solving the problem

[0009] A pressure sensor module according to the present invention is a pressure sensor comprising: a thin plate-shaped diaphragm that can be displaced by the pressure of a fluid to be detected; and a detection unit that is disposed on the diaphragm and detects displacement of the diaphragm. A sensor module, wherein the sensor module is disposed to face a surface of the diaphragm opposite to the surface on the side of the detection unit, and is provided via a holding space formed by a holding member, and is configured to receive the fluid to be detected. A thin film layer capable of being displaced by pressure, a displacement transmitting portion for transmitting the displacement of the thin film layer to the diaphragm, and a vent communicating the holding space and the external space.

[0010] According to the present invention, the holding space is provided between the diaphragm and the thin film layer, and the holding space is provided with the ventilation hole communicating with the external space. As a result, even if, for example, corrosive gas components of the detected fluid permeate the thin film layer, they are formed in the holding space. It becomes possible to remove or dilute these corrosive gas components from the vent holes. Therefore, even when used for a long time, the diaphragm is not corroded by corrosive gas or chemical solution, so that the detection accuracy can be maintained and the life of the pressure sensor module can be extended.

Further, in the present invention, it is preferable that the holding member is an annular member formed on the outer periphery of the diaphragm and the thin film layer.

According to the present invention, the annular member is annularly formed on the outer periphery of the diaphragm and the thin film layer to form a holding space. Thereby, the holding space for the height dimension of the annular member can be reliably secured. Further, since the annular member is formed on the outer periphery of the diaphragm and the thin film layer, the pressure of the fluid to be detected can be received by the entire thin film layer on the inner side of the annular member. Therefore, the pressure detection accuracy of the pressure sensor module is improved.

[0012] Further, it is preferable that a plurality of the ventilation holes are formed in the annular member.

According to this invention, a plurality of air holes are formed in the holding space. Thus, the holding space can be ventilated to the outside of the plurality of vent hole force cases. Therefore, even if the corrosive gas component of the fluid to be detected permeates from the thin film layer to the holding space, the corrosive gas component of the fluid to be detected can be efficiently removed or diluted by the plurality of ventilation holes. In addition, a part of the plurality of vents is used as an exhaust vent for removing corrosive gas components of the fluid to be detected that has passed through the holding space, and the remaining vents are used to remove corrosive gas components of the fluid to be detected. It may be a ventilation hole for inflow to positively replace the holding space that has become a corrosive gas atmosphere due to permeation. In this case, the corrosive gas component permeated into the holding space can be washed away, and the holding space can be more efficiently ventilated. Therefore, it is possible to reliably prevent the corrosion of the diaphragm due to the permeation of the corrosive gas component of the fluid to be detected.

[0013] Further, it is preferable that the displacement transmitting section is provided substantially on a central axis of the holding space.

In the present invention, the displacement transmitting section is provided on a substantially central axis of the holding space, for example, on the axis of the cylinder when the holding space is formed in a cylindrical shape surrounded by an annular member. Thus, the displacement transmitting section can transmit the displacement at the approximate center of the thin film layer, which causes the largest displacement due to the pressure of the fluid to be detected, to the diaphragm. Therefore, the thin layer The displacement can be reliably transmitted to the diaphragm.

[0014] Further, it is preferable that the displacement transmitting section is provided by connecting a substantially center of the thin film layer and a substantially center of the diaphragm.

According to the present invention, the displacement transmitting section is fixed to both the diaphragm and the thin film layer, and connects the diaphragm and the thin film layer. Thus, even when the thin film layer is displaced in the direction away from the diaphragm force due to the negative pressure, or when the thin film layer is displaced only by a small amount due to the minute pressure, the displacement of the thin film layer can be reliably transmitted to the diaphragm. Therefore, the detection accuracy of the pressure of the fluid to be detected can be maintained with high accuracy.

[0015] The thin film layer is formed in a substantially cup shape having a bottom surface facing the diaphragm, and a cylindrical portion extending from an outer peripheral portion of the bottom surface to a side opposite to the diaphragm. Preferably, an outer peripheral end of the tubular portion is fixed to the holding member.

According to the present invention, the thin film layer is formed in a substantially cup shape, and the outer peripheral portion of the cup is fixed. Thus, the pressure of the side of the thin film layer opposite to the diaphragm, that is, the pressure received by the pressure receiving surface can be dispersed throughout the cup-shaped thin film layer in which stress is not concentrated on a local portion around the displacement transmitting portion. Therefore, a sufficient withstand voltage can be maintained even if the thickness of the thin film layer is reduced, and the accuracy of the pressure sensor module is improved by reducing the thickness of the thin film layer.

[0016] Further, it is preferable that the displacement transmitting portion protrudes toward the diaphragm at a substantially central position of the bottom portion, and is formed in a state in which the displacement transmitting portion is curved toward a front end of the displacement transmitting portion. ,.

According to the present invention, the boundary between the thin film layer and the displacement transmitting section is curved. This makes it possible to disperse the pressure applied to the curved portion of the boundary where the pressure received on the pressure receiving surface does not concentrate at one point of the boundary. Therefore, it is possible to further improve the pressure resistance of the thin film layer.

[0017] Further, it is preferable that a protruding portion that protrudes and is formed to be curved toward a front end of the surface force of the bottom surface portion is provided on a side of the bottom surface portion opposite to a side on which the displacement transmission unit is provided.

According to the present invention, the thin film layer protrudes toward the pressure receiving surface side in a state where the boundary with the thin film layer is curved. A part is provided. Thus, the pressure received by the thin film layer can be dispersed even in the curved portion of the protrusion provided on the pressure receiving surface side. Thereby, the pressure received on the pressure receiving surface can be more dispersed.

Further, it is preferable that the thin film layer, the holding member, and the displacement transmitting portion are integrally formed!

According to the present invention, since the thin film layer, the holding member, and the displacement transmitting section are integrally formed, the number of components can be reduced, and the configuration is simplified. Further, pressure resistance can be maintained such that the thin film layer and the displacement transmitting portion, and the thin film layer and the protruding portion are not separated.

Further, it is preferable that the thin film layer, the annular member, and the displacement transmitting section are integrally formed.

According to the present invention, since the thin film layer, the annular member, and the displacement transmitting portion are integrally formed, the annular member and the displacement transmitting portion do not separate from the thin film layer. Therefore, the thin film layer, the annular member, and the displacement transmitting portion do not deteriorate due to separation or the like even when used for a long time. Further, since the thin film layer, the annular member, and the displacement transmitting section are integrally formed, the work of bonding the thin film layer to the annular member and the displacement transmitting section can be omitted, and the productivity is improved.

[0020] In the present invention, the thin film layer is preferably made of fluorine resin.

According to the present invention, fluorine resin is used for the thin film layer. Fluorine resin has excellent corrosion resistance, so that even when a highly corrosive fluid to be detected is used, the corrosion of the diaphragm can be prevented. For example, when Teflon resin (registered trademark of "I" Dupont Dou "Numur" and "Campa-I") or the like is used as the fluorine film resin, the diaphragm can be more reliably used than the corrosive force of the fluid to be detected. Can be prevented.

[0021] Further, in the present invention, a pedestal portion is provided so as to face a detection portion side surface of the diaphragm, and the detection portion is provided on a detection portion side surface of the diaphragm and a surface of the pedestal portion on the diaphragm side. It is preferable to form a capacitor by the pair of electrodes provided. According to the present invention, the pressure sensor module includes the pedestal portion facing the diaphragm, and the detecting portion includes a pair of the pair provided on the surfaces of the diaphragm and the pedestal portion facing each other. It has electrodes. As a result, a capacitor is formed by these electrodes, and the capacitance of the capacitor changes based on the amount of displacement of the diaphragm. Then, the detection unit can detect the pressure of the fluid to be detected by detecting the change in the capacitance. The detecting unit that detects a change in capacitance can accurately detect even a small displacement of the diaphragm, and further has a small error, thereby enabling highly accurate pressure detection.

[0022] In the present invention, it is preferable that the strain detection unit is disposed at a predetermined distance from the diaphragm, and is provided on an elastically deformable detection unit main body connected to the diaphragm by a connection unit.

According to the present invention, the strain detecting section is provided in the detecting section main body connected to the diaphragm. Thus, when the main body of the detecting section is elastically deformed by the displacement of the diaphragm, the strain detecting section can detect the amount of deformation of the main body of the detecting section and obtain the amount of displacement of the diaphragm. Therefore, pressure can be easily detected with a simple configuration.

Further, in the present invention, the detection unit may be arranged in contact with the diaphragm.

According to the present invention, the strain gauge is directly attached to the diaphragm. Thereby, the configuration of the pressure sensor module can be further simplified. Therefore, production costs can be reduced. Furthermore, since the strain gauge is provided directly on the diaphragm, the amount of displacement of the diaphragm can be directly detected. Therefore, detection accuracy of the fluid to be detected can be improved.

In the present invention, it is preferable that a thin film is attached to a surface of the diaphragm on the thin film layer side.

According to the present invention, the thin film is attached to the opening side of the diaphragm. As a result, even if the corrosive gas component of the fluid to be detected permeates the thin film layer, the diaphragm is protected by the thin film, so that the corrosive gas component can be immediately removed from the ventilation hole that is not corroded. Can be removed or diluted. Therefore, the corrosion of the diaphragm can be more reliably prevented, and the life of the pressure sensor module can be more reliably extended.

[0025] The pressure detection device of the present invention includes a case having an opening through which the fluid to be detected is introduced, and the pressure sensor module as described above, and the thin film layer covers the opening. A pressure detecting device, wherein the vent communicates the holding space with an outside of the pressure detecting device.

According to the present invention, the diaphragm is not corroded by a corrosive gas or a chemical solution even when used for a long time, so that the detection accuracy can be maintained and the life of the pressure testing device can be extended.

[0026] It is preferable that the case includes the holding member in a part thereof, and that a holding space is formed between the diaphragm and the thin film layer by fixing an outer peripheral portion of the thin film layer. According to the present invention, the holding member is provided in the case, and the thin film layer is fixed to the case to form a holding space. According to the present invention, it is possible to substitute a part of the case without separately providing a holding member, thereby improving productivity.

Further, the case includes an upper case portion disposed on the diaphragm side of the thin film layer, and a lower case portion disposed on the opposite side of the thin film layer from the diaphragm. It is preferable that the upper case and the lower case are sandwiched and fixed.

According to the present invention, the thin film layer can be easily fixed by sandwiching the thin film layer between the upper case portion and the lower case portion. At this time, if the thin film layer is formed of an elastic synthetic resin such as Teflon (registered trademark of I-I-I, Dupont, Dough, Nmour, and Campa-I), the upper case and the lower case may be used. The tightness can be sufficiently improved by sandwiching the thin film layer between the portions.

[0028] Further, at least one of the upper case portion and the lower case portion has a fixing groove in at least a part of a position where the thin film layer is fixed, and the thin film layer has an outer peripheral portion. According to the present invention, it is preferable that a fixing projection is provided to be fitted in the fixing groove, and the fixing projection is fitted and fixed to the fixing groove so as to be sandwiched and fixed between the upper case and the lower case. By fitting the fixing protrusion of the thin film layer into the fixing groove provided in the lower part or the lower case part, the fixing of the thin film layer can be strengthened, and the tightness of the thin film layer and the case can be further improved. Can be.

Brief Description of Drawings

FIG. 1 is a cross-sectional view showing a pressure transmitter according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view showing a pressure sensor module and a pressure receiving unit according to the first embodiment.

FIG. 3 is a sectional view showing a pressure transmitter according to a second embodiment of the present invention.

FIG. 4 is an enlarged cross-sectional view illustrating a part of a cup-shaped pressure-receiving thin film according to a second embodiment.

FIG. 5 is an enlarged cross-sectional view showing a part of a cup-shaped pressure-receiving thin film according to a second embodiment.

FIG. 6 is a cross-sectional view showing a pressure transmitter according to another embodiment of the present invention.

FIG. 7 is a cross-sectional view showing a pressure transmitter according to still another embodiment of the present invention.

FIG. 8 is a cross-sectional view showing a pressure transmitter according to still another embodiment of the present invention.

FIG. 9 is a cross-sectional view showing a pressure transmitter according to still another embodiment of the present invention.

FIG. 10 is a cross-sectional view showing a pressure transmitter according to still another embodiment of the present invention.

FIG. 11 is a sectional view showing a pressure sensor module according to still another embodiment of the present invention.

FIG. 12 is an exploded perspective view showing the pressure sensor module in FIG.

Explanation of symbols

[0030] 1 ... pressure transmitter as pressure detecting device, 2 ... pressure sensor module, 10 ... case, 10A ... opening, 13 ... pedestal, 21 ... detection board as detecting unit, 22 ··· Diaphragm, 23 ··············································································· Lot , 34 ... holding space, 71 ... cup-shaped pressure receiving thin film as thin film layer, 72 ... lot part as displacement transmitting part, 73 ... projecting part, 110A ... upper case, 110Β ... lower Case, 110D… Fixing groove, 321 ·····························································································································································

BEST MODE FOR CARRYING OUT THE INVENTION

[First Embodiment]

Hereinafter, a pressure transmitter according to a first embodiment of the present invention will be described with reference to the drawings.

(Configuration of Pressure Transmitter of First Embodiment)

In FIG. 1, a pressure transmitter 1 as a pressure detecting device is located at a predetermined position in a pipe. And a pressure measuring device connected to the pipe and measuring the pressure of the fluid to be detected flowing in the pipe. Here, the force described for the pressure transmitter 1 is not limited to this. For example, the pressure transmitter 1 may be used for a pressure switch that detects indoor pressure and generates a different signal depending on the pressure value. Further, in the present embodiment, the fluid to be detected that can be measured by the pressure transmitter 1 will be described using a highly corrosive gas or a fluid such as a chemical solution. However, the present invention is not limited to this. It can be used for pressure detection of various fluids such as liquid and gel. The pressure transmitter 1 includes a case 10 formed as a substantially cylindrical case having an opening 10A at one end, a capacitance sensor element 20 stored in the case 10, for example, and a fluid to be detected. A pressure receiving unit 30 for receiving the pressure of the pressure, a conversion circuit 40 for converting a change in capacitance of the pressure sensor element 20 into a predetermined electric signal, and a joint (not shown) for guiding a fluid to be detected to the pressure receiving unit 30. ing. The pressure sensor module 2 is constituted by a pressure sensor element 20 provided inside the case 10 and opposed to one surface of a pedestal section 13 described later, a pressure receiving section 30, and the like.

The case 10 includes a first case 11 provided with an opening 10 A, and a second case 12 fixed to the first case 11.

The first case 11 is formed in a substantially cylindrical shape surrounding a periphery of the pressure sensor element 20 and the pressure receiving portion 30 by fitting a joint (not shown) to the substantially circular opening 10A. The first case 11 includes a communication hole 111 to be described later and a concave portion 112 formed along the outer peripheral edge of the pressure receiving portion 30 on the opening 10A side. The concave portion 112 is formed in a substantially annular shape, and a sealing member 113 such as an O-ring made of, for example, fluororubber or Kalrez is provided between the concave portion 112 and the pressure receiving portion 30 to complete the sealing process. Is given. This prevents the fluid to be detected from entering the inside of the pressure receiving section 30 or the communication hole 111 from the opening 10A.

[0035] A joint (not shown) is connected to the opening 10A. The joint is inserted into the opening 10A of the first case 11 and has a pressure introducing part (not shown) for introducing the fluid to be detected into the pressure receiving part 30 provided inside the first case 11.

Further, a substantially cylindrical pedestal portion 13 is formed on a substantially central axis of the first case 11. The pressure sensor element 20 is attached to the opening 10A side of the pedestal 13. Ma In addition, a through hole is formed in the pedestal portion 13 for inserting a wiring 41 that electrically connects the pressure sensor element 20 and the conversion circuit 40. Further, the pedestal portion 13 is provided with a pressure adjustment for communicating a displacement space 25 formed between the pedestal portion 13 and a diaphragm 22 of a pressure sensor element 20 described later with the internal space of the second case 12. A hole 115 is formed.

The second case 12 is formed to cover one end of the first case 11 on the side opposite to the opening 10A. On the inner peripheral side of the second case 12, for example, a mounting piece 14 is formed so as to protrude inward. By screwing the mounting piece 14 from the first case 11 to the mounting piece 14, The second case 12 is fixed. Further, a seal member 114 is attached between the first case 11 and the second case 12, so that the structure is completely sealed.

[0038] In the second case 12, an electric signal wiring 42 connected to the conversion circuit 40 and a tube 51 for connecting the internal space of the second case 12 with the outside of the case 10 are bundled in a single bundle 50. There is provided a through hole 121 for passing through. A female screw portion is formed on the inner peripheral surface of the through hole 121, and the first cap 15 is screwed into the female screw portion. The first cap 15 is screwed into the through hole 121 in a state where a seal member is wound around the external thread of the first cap 15 in order to maintain the hermeticity of the case 10. Then, on the shaft of the first cap 15, there is formed a communication portion 151 through which the cable 50 passes. A seal member 152 is provided between the communication portion 151 and the cable 50 to maintain the hermeticity of the communication portion 151. The distal end of the first cap 15 is formed with a male screw portion, and is screwed to the second cap 16. The cable 50 is fixed by the second cap 16.

As shown in FIG. 2, the pressure sensor element 20 includes a detection board 21 formed on the surface of the pedestal section 13 on the side of the opening 10A, and a diaphragm 22 arranged to face the detection board 21. ing. The diaphragm 22 is attached via a joining glass 23 as a substantially annular insulating member formed along the outer peripheral edge of the pedestal portion 13 on the opening 10A side. The bonding glass 23 is closely fixed to the pedestal portion 13 and the diaphragm 22 by, for example, an adhesive to form a substantially closed displacement space 25. Further, the displacement space 25 can be ventilated to the outside from the above-described pressure adjusting hole 115 via the second case 12 and the tube 51. For this reason, the pressure in the displacement space 25 can be maintained at an external pressure, for example, atmospheric pressure.

[0040] The diaphragm 22 is formed in a substantially disk shape. Diaphragm 22 is The outer peripheral edge is bonded and fixed to the bonding glass 23, and the outer peripheral edge is formed so as to contact the inner peripheral surface of the first case 11. The inside of the surface of the diaphragm 22 surrounded by the bonding glass 23 is formed so as to be displaceable in the axial direction in accordance with a change in the pressure of the fluid to be detected. In this embodiment, as the diaphragm 22, a force using a ceramic diaphragm excellent in wear resistance, chemical resistance, heat resistance, and insulation is not limited. Alternatively, a silicon diaphragm or the like can be used. However, when a metal diaphragm is used, it is preferable to electrically insulate an electrode, which will be described later, formed on the diaphragm from the diaphragm by attaching an insulating thin film to the metal surface. Further, a thin film 24 is attached to a side surface of the pressure receiving portion 30 of the diaphragm 22. Examples of the thin film 24 include polytetrafluoroethylene (PTFE: Poly TetraFluoroEthylene), perfluoroalkoxy alkane (PFA), and tetrafluoroethylene'hexafluoropropylene copolymer (PFA). FEP: TetrafluoroEt hyrene / hexafluoroPropylene) ゃ tetrafluoroethylene'ethylene copolymer (ETFE: Ethylene / TetraFluoroEthylene), bi-lidene fluoride (PVDF: PolyVinyliDeneFluoride) and polychlorinated trifluoroethylene (PCTFE: PolyChloroTriFluoroEthylene) ) Can be used. All of these fluororesins have excellent chemical resistance and are not affected by corrosive gases or chemicals. The thin film 24 is not limited to these fluorine resins, but may be made of other materials having excellent corrosion resistance, for example, high-density polyethylene. However, even these fluororesins and other materials with excellent corrosion resistance may have properties such as being eroded by a specific organic solvent. It is preferable to select the material.

On a surface of the detection substrate 21 and the diaphragm 22 facing each other, a pair of electrodes as a detection unit is formed with the displacement space 25 interposed therebetween. Here, when the pressure of the fluid to be detected fluctuates, the diaphragm 22 is displaced according to the pressure, and the capacitance of the pressure sensor element 20 changes. Further, a wiring 41 whose one end is connected to the conversion circuit 40 through the through hole of the pedestal 13 is connected to the detection board 21 and the diaphragm 22. Then, the conversion circuit 40 detects a change in the capacitance of the electrodes provided on the detection substrate 21 and the diaphragm 22, converts the change into a voltage output signal, and is connected by the electric signal wiring 42. Output to the measuring device.

[0042] The pressure receiving section 30 is provided on the opening 10A side of the diaphragm 22. The pressure receiving portion 30 includes a substantially disc-shaped thin film layer 31 that contacts the fluid to be detected at the opening 10A side, and an annular member that is adhered and fixed to the outer peripheral portion of the diaphragm 22 and holds the thin film layer 31. And a lot 33 as a displacement transmission unit provided between the thin film layer 31 and the diaphragm. The thin film layer 31, the annular member 32, and the lot 33 are bonded by fusion thermocompression bonding. In addition, the thin film layer 31, the annular member 32, and the lot 33 may be integrally formed with a fluorine resin. In this case, since the bonding operation or the like can be omitted, productivity can be improved. Further, since the thin film layer 31 and the annular member 32 and the lot 33 do not peel off, the life of the pressure sensor module 2 can be extended.

The thin film layer 31 is formed of various fluorine resins such as PTFE, PFA, ETFE, FEP, PVDF, and PCTFE having excellent corrosion resistance, and other synthetic resins having corrosion resistance, similarly to the thin film 24 described above. ing. The outer peripheral portion of the thin film layer 31 on the side of the diaphragm 22 and the annular member 32 are tightly fixed by, for example, adhesion or fusion, and are integrally formed. As described above, the annular sealing member 113 is provided between the opening 10A side of the outer peripheral portion of the thin film layer 31 and the first case 11, and is sealed.

The annular member 32 is formed in a cylindrical shape having a predetermined height, for example, and forms a holding space 34 between the diaphragm 22 and the thin film layer 31. The annular member 32 may be formed of a material such as, for example, a corrosion-resistant fluorine resin or the like, or may be formed by coating the surface of a synthetic resin or metal having a hardness with a fluorine resin or the like. ,. In the annular member 32, a plurality of ventilation holes 321 penetrating from the outer peripheral surface to the inner peripheral surface are formed at predetermined intervals. Further, as shown in FIGS. 1 and 2, these ventilation holes 321 are formed at positions that are symmetric with respect to a substantially center point of the annular member 32. The ventilation hole 321 is connected to the communication hole 111 of the first case 11. As described above, since the communication hole 111 communicates with the outside of the first case 11, the holding space 34 can ventilate to the outside of the case 10 through the ventilation hole 321 and the communication hole 111. ing. Therefore, for example, even if the corrosive gas component of the detected fluid permeates the thin film layer 31 and permeates the holding space 34, the detected fluid is passed through the vent hole 321 and the communication hole 111 to the first case 11. Outside atmosphere Can be replaced with atmosphere. Note that a pump or the like may be connected to the communication hole 111, for example. With such a configuration, since the inside of the holding space 34 can be efficiently ventilated, even if the corrosive gas component of the fluid to be detected permeates the holding space 34, the corrosive gas component can be efficiently removed or diluted.

[0045] The lot 33 is formed in a column shape having the same height as the annular member 32 in height. The lot 33 is provided substantially on the central axis of the holding space 34, that is, is provided by connecting the substantially center of the diaphragm 22 and the substantially center of the thin film layer 31, and is provided by connecting the diaphragm 22 and the thin film layer 31. Has been. The other end of the lot 33 is fixedly attached to the diaphragm 22. The lot 33 transmits the displacement to the diaphragm 22 when the thin film layer 31 is displaced by receiving the pressure of the fluid to be detected. Therefore, it is preferable that the lot 33 is a material having a relatively high hardness and which does not bend when the thin film layer 31 is displaced. Further, it is preferable that the lot 33 is formed of a material having a low density so that the thin film layer 31 is not bent by the weight of the lot 33. In order to reduce the gravity of the lot 33, the lot 33 may have a hollow shape.

(Operation and Effect of Pressure Transmitter of First Embodiment)

In the pressure sensor module 2 of the pressure transmitter 1 according to the first embodiment as described above, a holding space 34 is formed between the diaphragm 22 and the thin film layer 31, and the holding space 34 is provided outside the first case 11. A vent 321 and a communicating hole 111 are provided. Therefore, when a corrosive gas or a chemical solution is used as the fluid to be detected, for example, even if the corrosive gas or the corrosive gas component of the chemical solution permeates from the thin film layer 31 to the holding space 34, the holding space 34 It is possible to remove or dilute the fluid to be detected that has passed through the communication hole 111 from the ventilation hole 321 formed in the case 10 to the outside of the case 10. Therefore, for example, even when the pressure sensor module 2 is used for a long time, the corrosive gas component that has permeated the thin film layer 31 can be immediately removed or diluted, and the corrosion of the diaphragm 22 by the fluid to be detected can be prevented. Accordingly, the measurement accuracy of the pressure sensor module 2 can be maintained for a long time, and the durability of the pressure sensor module 2 can be maintained for a long time, so that the life of the pressure sensor module 2 can be extended.

[0047] The annular member 32 is formed in an annular shape on the outer periphery of the diaphragm 22 and the thin film layer 31. Thus, a holding space 34 is formed. Therefore, the holding space 34 corresponding to the height of the annular member 32 can be reliably secured. Further, since the annular member 32 is adhered to the outer periphery of the diaphragm 22 and the thin film layer 31, the pressure of the fluid to be detected can be received in the entire inside of the annular member 32, and the pressure detection accuracy of the pressure sensor module 2 is improved. Can be achieved.

[0048] In the holding space 34, a plurality of ventilation holes 321 are formed. For this reason, the holding space 34 can ventilate to the outside of the case 10 from the plurality of ventilation holes 321 through the communication holes 111. Therefore, even when the corrosive gas component of the fluid to be detected permeates through the holding space 34 from the thin film layer 31, the corrosive gas component permeated into the holding space 34 can be removed by the plurality of ventilation holes 321. In addition, a part of the plurality of vents 321 is used as an exhaust vent 321 for removing corrosive gas components of the fluid to be detected that has passed through the holding space 34, and the remaining vent 321 is used for the fluid to be detected. In order to actively replace the holding space 34 that has become a corrosive gas atmosphere due to the permeation of corrosive gas components, it can also be used as a ventilation hole 321 for inlet. In this case, ventilation of the holding space 34 is more efficient. Can be. Therefore, corrosion of the diaphragm 22 due to corrosive gas or chemical solution can be reliably prevented.

The lot 33 is provided on a substantially central axis of a holding space 34 that connects the substantially center of the diaphragm 22 and the substantially center of the thin film layer 31. For this reason, since the lot 33 is provided at the position where the displacement of the thin film layer 31 due to the pressure of the fluid to be detected is largest, the displacement amount of the thin film layer 31 can be reliably transmitted to the diaphragm 22 via this lot 33.

[0050] As described above, the thin film layer 31, the annular member 32, and the lot 33 of the pressure receiving unit 30 may be integrally formed. In this case, the corrosive gas component of the fluid to be detected is retained in the holding space. Even if it penetrates into the inside of 34, the annular member 32 and the lot 33 do not peel off from the thin film layer. Therefore, the thin film layer 31, the annular member 32, and the lot 33 can be prevented from being deteriorated due to separation or the like even when used for a long time. Further, since the thin film layer 31, the annular member 32, and the port 33 are integrally formed, the work of bonding the thin film layer 31, the annular member 32, and the lot 33 can be omitted, and the productivity is improved.

[0051] As a material of the thin film layer 31, fluorine resin is used. For this reason, such fluororesins have excellent corrosion resistance, so that they do not erode even when a highly corrosive gas or chemical solution is used as the fluid to be detected. Chemical corrosion The permeation of the reactive gas component into the holding space can be efficiently prevented.

[0052] Further, pressure transmitter 1 fixes detection capacitor 21 to pedestal portion 13 fixed in case 10, and forms electrodes on opposing surfaces of detection substrate 21 and diaphragm 22 to form a capacitor. Has formed. Therefore, the capacitance of the capacitor changes according to the displacement of the diaphragm 22, and the pressure of the fluid to be detected can be measured according to the change in the capacitance. Therefore, even if the diaphragm 22 is displaced by only a small amount, pressure can be measured with high accuracy and little error.

The thin film 24 is attached to the opening 10A side of the diaphragm 22. For this reason, even if the corrosive gas component of the test fluid permeates from the thin film layer 31 into the holding space 34, the corrosion of the diaphragm 22 can be prevented because the diaphragm 22 is protected by the thin film 24. And since such a corrosive gas component can be immediately removed or diluted from the vent hole, the thin film 24 does not peel off due to the permeated corrosive gas component. Therefore, the corrosion of the diaphragm can be more reliably prevented, and the life of the pressure sensor module can be more reliably prolonged.

The vent hole 321 is formed at a position symmetrical with respect to a substantially center point of the annular member 32. Therefore, by flowing air from one ventilation hole 321 to the other ventilation hole 321, a smooth ventilation channel can be formed. Therefore, the ventilation efficiency of the holding space 34 can be improved.

[Second Embodiment]

Next, a pressure transmitter according to a second embodiment of the present invention will be described with reference to the drawings. In the following description, parts already described in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted or simplified.

(Configuration of Pressure Transmitter of Second Embodiment)

In FIG. 3, a pressure transmitter 1A as a pressure detecting device is connected to a predetermined position in a pipe and is a fluid to be detected as a fluid to be detected flowing through the pipe, similarly to the pressure transmitter 1A of the first embodiment. It is a pressure measuring device for measuring the pressure of the pressure. Further, as the fluid to be detected that can be measured by the pressure transmitter 1A, similarly to the first embodiment, a highly corrosive gas or a fluid such as a chemical solution will be described, but is not limited thereto. So It can be used for pressure detection of various fluids such as other gases, liquids, and gels. The pressure transmitter 1A includes a case 10 formed in a substantially cylindrical shape having an opening 10A at one end, a capacitance type pressure sensor element 20 stored in the case 10, and a fluid to be detected. A pressure receiving part 70 for receiving pressure, a conversion circuit 40 for converting a change in capacitance of the pressure sensor element 20 into a predetermined electric signal, and a joint (not shown) for guiding a fluid to be detected to the pressure receiving part 70 are provided. Have. Then, a pressure sensor module 2A is constituted by a diaphragm 22, a pressure sensor element 20, a pressure receiving section 70, and the like, which are disposed to face one surface of a pedestal portion 13 described later provided inside the case 10.

[0057] The case 10 includes a first case 11 provided with an opening 10A and a second case 12 fixed to the first case 11, similarly to the case 10 of the first embodiment. You.

[0058] The first case 11 is formed in a substantially cylindrical shape surrounding a periphery of the pressure sensor element 20 and the pressure receiving part 70 by a joint (not shown) being engaged with the substantially circular opening 10A. Further, the first case 11 includes an upper case 110A that has a communication hole 111 as a ventilation hole and also functions as a holding member, and a lower case 110B that can be fitted to the upper case 110A. . Further, the upper case 110A is formed with a concave portion 110C for sandwiching the thin film fixing portion 713 on the inner peripheral surface side of the boundary position with the lower case 110B. Further, in the lower case 110B, a substantially annular fixing groove 110D is formed at a predetermined position facing the concave portion 110C so as to have a tapered shape in which a width dimension decreases as the distance from the upper case 110A increases.

[0059] The joint connected to the opening 10A is inserted into the inside of the opening 10A of the first case 11, and introduces the fluid to be detected into the pressure receiving unit 70 provided inside the first case 11. Not shown! A pressure inlet is provided.

Further, a substantially cylindrical pedestal portion 13 is arranged on a substantially central axis of the upper case 110A of the first case 11. The pressure sensor element 20 is attached to the opening 10A side of the pedestal 13. A sensor holding member 90 such as an O-ring is provided between a part of the inner peripheral surface of the upper case 110A of the first case 11 and the pressure sensor element 20. Further, the pedestal portion 13 is formed with a through hole through which a wiring 41 for electrically connecting the pressure sensor element 20 and the conversion circuit 40 is inserted. Further, the pedestal portion 13 includes a displacement space 25 formed between the pedestal portion 13 and the diaphragm 22 of the pressure sensor element 20, and a second case. A pressure adjusting hole 115 communicating with the internal space 12 is formed.

[0061] The second case 12 is formed to cover one end of the first case 11 on the side opposite to the opening 10A. On the inner peripheral side of the second case 12, for example, a mounting piece 14 is formed so as to protrude inward. By screwing the mounting piece 14 from the first case 11 to the mounting piece 14, The second case 12 is fixed. Further, a seal member 114 is attached between the first case 11 and the second case 12, so that the structure is completely sealed.

[0062] Further, the second case 12 includes an electric signal wiring 42 connected to the conversion circuit 40, and a tube 51 that connects the internal space of the second case 12 and the outside of the case 10 in a bundle. A through-hole 121 for passing through 50 is provided. The first cap 15 is screwed into a female screw portion formed on the inner peripheral surface of the through hole 121. The first cap 15 is screwed into the through hole 121 in a state where a seal member is wound around an external thread of the first cap 15 in order to maintain the hermeticity of the case 10. Then, on the axis of the first cap 15, there is formed a through portion 151 through which the cable 50 passes. A seal member 152 is provided between the communication part 151 and the cable 50 to maintain the airtightness of the communication part 151. Further, a male screw portion is formed at the tip of the first cap 15, and the second cap 16 is screwed. The cable 50 is fixed by the second cap 16.

As in the first embodiment, the pressure sensor element 20 includes a detection board 21 formed on the surface of the pedestal section 13 on the side of the opening 10A, and a diaphragm 22 arranged to face the detection board 21. , Is provided. Diaphragm 22 is attached via bonding glass 23. The bonding glass 23 is closely fixed to the pedestal portion 13 and the diaphragm 22 by, for example, an adhesive to form a substantially sealed displacement space 25. And, as described above, the displacement space 25 can be ventilated to the outside from the pressure adjustment hole 115 via the second case 12 and the tube 51. Thus, the pressure in the displacement space 25 is maintained at an external pressure, for example, the atmospheric pressure.

[0064] As in the first embodiment, the diaphragm 22 is formed substantially in a disk shape. As described above, the diaphragm 22 is formed such that the outer peripheral end is bonded and fixed to the bonding glass 23 and the outer peripheral edge is in contact with the inner peripheral surface of the first case 11. In addition, the inside of the surface of the diaphragm 22 that is surrounded by the bonding glass 23 is moved in the axial direction according to a change in the pressure of the fluid to be detected. It is formed so that it can be displaced. As the diaphragm 22, as in the first embodiment, a ceramic diaphragm having excellent wear resistance, chemical resistance, heat resistance, and insulation properties is used, but is not limited thereto, and may be formed of, for example, stainless steel. For example, a metal diaphragm or a silicon diaphragm can be used. However, in the case of using a metal diaphragm, it is preferable to electrically insulate an electrode described later formed on the diaphragm from the electrode by attaching an insulating thin film to the metal surface. The thin film 24 is attached to the side surface of the pressure receiving section 70 of the diaphragm 22. As the thin film 24, as in the first embodiment, for example, polytetrafluoroethylene (PTFE: PolyTetraFluoroEthylene), perfluoroalkoxyalkane (PFA: PerFluoroAlkoxylalkane), tetrafluoroethylenhexafluoro Propylene copolymer (FEP: TetrafluoroEthyrene / hexafluoroPropylene) ゃ tetrafluoroethylene エチレン Ethylene copolymer (ETFE: Ethylene / TetraFluoroEthylene), bi-lidene fluoride resin (PVDF: PolyVinyliDeneFluoride), and polychlorinated trifluoroethylene Various fluororesins such as (PCTFE: PolyChloroTriFluoroEthylene) can be used. All of these fluororesins have excellent chemical resistance and are not affected by corrosive gases or chemicals. The thin film 24 is not limited to these fluorine resins, but may be made of other materials having excellent corrosion resistance, for example, high-density polyethylene. However, even these fluororesins and other materials with excellent corrosion resistance may have properties such as being eroded by a specific organic solvent. It is preferable to select the material.

As in the first embodiment, a pair of electrodes as a detection unit is formed on the surfaces of the detection substrate 21 and the diaphragm 22 that face each other, as in the first embodiment. Here, when the pressure of the fluid to be detected fluctuates, the diaphragm 22 is displaced according to the pressure, and the capacitance of the pressure sensor element 20 changes. Further, a wiring 41 whose one end is connected to the conversion circuit 40 through the through hole of the pedestal 13 is connected to the detection board 21 and the diaphragm 22. Then, the conversion circuit 40 detects a change in the capacitance of the electrodes provided on the detection substrate 21 and the diaphragm 22, converts the change into a voltage output signal, and outputs the voltage output signal to the measurement device connected by the electric signal wiring 42. I do.

[0066] The pressure receiving section 70 is provided on the opening 10A side of the diaphragm 22. This pressure receiving part 70 A cup-shaped pressure-receiving thin film 71 as a thin film layer, a lot portion 72 as a displacement transmitting portion formed integrally with the cup-shaped pressure-receiving thin film 71, and a projecting portion 73 formed integrally with the cup-shaped pressure-receiving thin film 71. ing.

The cup-shaped pressure receiving thin film 71 includes a bottom portion 711, a cylindrical portion 712, and a thin film fixing portion 713. The bottom portion 711 is arranged at a position facing the thin film 24 and is formed in a substantially disk shape. Further, the cylindrical portion 712 is formed by bending and extending from the outer peripheral portion of the disk of the bottom portion 711 toward the opening 10A. By the bottom portion 711 and the cylindrical portion 712, the cup-shaped pressure-receiving thin film 71 is formed in a substantially cup-like shape in which the diaphragm 22 side is convex. The thin film fixing portion 713 is provided at an outer peripheral end of the cylindrical portion 712, and is formed thicker than the cylindrical portion 712. Further, the thin film fixing portion 713 includes a fixing protrusion 713A protruding toward the opening 10A and a fixing flange 713B extending along a radial direction moving away from the axis of the cup-shaped pressure receiving thin film 71. It is formed. Then, as shown in FIG. 4, the cup-shaped pressure receiving thin film 71 is fixed with the thin film fixing portion 713 sandwiched between the upper case 110A and the lower case 110B of the first case 11. That is, the cup-shaped pressure-receiving thin film 71 makes the fixing flange 713B of the thin film fixing portion 713 adhere to the concave portion 110C of the upper case 110A, and the sealing member 80 such as an O-ring is provided between the fixing flange 713B and the lower case 110B. In this state, the fixing protrusion 713A of the thin film fixing portion 713 is fixed by fitting the fixing protrusion 713A into the fixing groove 110D of the lower case 110B. Then, a holding space 34 is formed between the cup-shaped pressure receiving thin film 71 and the diaphragm 22, and the holding space 34 and the external space of the pressure transmitter 1A are communicated by the communication hole 111.

The lot part 72 and the protruding part 73 are provided substantially at the center of the bottom part 711. The lot part 72 is provided on the diaphragm 22 side of the bottom part 711, and the protruding part 73 is provided on the opening 10A side of the bottom part 711. The lot 72 and the protrusion 73 are provided substantially symmetrically with respect to the bottom surface 711, that is, the lot 72 and the protrusion 73 have substantially the same diameter from the axis. And are formed in substantially the same shape, and are arranged coaxially. As shown in FIG. 5, the lot portion 72 has a curved portion 721 which is formed by drawing an arc having a predetermined diameter R from the surface of the bottom portion 711 on the side of the diaphragm 22 to the tip of the lot portion 72. ing. Similarly to the lot 72, the surface force on the opening 10A side of the bottom surface 711 is also applied to the tip of the projection 73 so that an arc of a predetermined diameter R is drawn on the projection 73. A curved portion 731 is formed. Further, the tip of the lot 72 is adhered and fixed to the approximate center of the diaphragm 22. The lot portion 72 transmits the displacement to the diaphragm 22 when the bottom surface portion 711 is displaced on the axis center by the cup-shaped pressure receiving thin film 71 receiving the pressure of the fluid to be detected.

(Operation and Effect of Pressure Transmitter of Second Embodiment)

As described above, in the pressure sensor module 2A of the pressure transmitter 1A according to the second embodiment, the holding space 34 is formed between the diaphragm 22 and the cup-shaped pressure receiving thin film 71, and the first case is formed in the holding space 34. A communication hole 111 communicating with the outside of 11 is provided. For this reason, similarly to the pressure transmitter 1 of the first embodiment, when a corrosive gas or a chemical solution is used as the fluid to be detected, for example, the corrosive gas or the corrosive gas component of the chemical solution is reduced to a thin film layer. Even if the fluid permeates from the space 31 to the holding space 34, the fluid to be detected that has passed through the communication hole 111 communicating with the holding space 34 to the outside of the case 10 can be removed or diluted. Therefore, for example, even when the pressure sensor module 2 is used for a long time, the corrosive gas component that has permeated the thin film layer 31 can be immediately removed or diluted, and corrosion of the diaphragm 22 by the fluid to be detected can be prevented. As a result, the measurement accuracy of the pressure sensor module 2 can be maintained for a long time, and the durability of the pressure sensor module 2 can be maintained for a long time, so that the life of the pressure sensor module 2 can be extended.

Further, the cup-shaped pressure-receiving thin film 71 is formed into a substantially cup with the diaphragm 22 side protruding by the bottom portion 711 and the cylindrical portion 712, and the outer peripheral portion of the cylindrical portion 712 is fixed to the first case 11. Have been. Therefore, the pressure of the detected fluid received by the surface of the cup-shaped pressure-receiving thin film 71 on the opening 10A side can be dispersed throughout the cup-shaped pressure-receiving thin film 71 without stress being concentrated on the lot portion 72. Therefore, the pressure resistance of the cup-shaped pressure receiving thin film 71 can be improved. Further, since the pressure resistance of the cup-shaped pressure-receiving thin film 71 is improved, sufficient pressure resistance can be ensured even if the thickness of the cup-shaped pressure-receiving thin film 71 is reduced. Since the sensitivity of the pressure sensor module 2A can be improved by reducing the size, the accuracy of pressure detection can be improved.

Further, the lot portion 72 is provided with a curved portion 721 which is curved from the surface of the bottom portion 711 to the tip so as to draw an arc having a predetermined diameter R. Therefore, the cup-shaped pressure receiving thin film 71 When the pressure is also applied to the fluid force to be detected, this pressure does not concentrate on one point at the boundary between the lot portion 72 and the bottom portion 711, and the stress can be dispersed throughout the curved portion 721. Therefore, the pressure resistance of the pressure-receiving pressure-receiving thin film 71 can be further improved.

Further, on the opening 10A side of the bottom portion 711 of the cup-shaped pressure receiving thin film 71, a protruding portion 73 having a curved portion 731 in which the surface force of the bottom portion 711 is curved with a predetermined radius R up to the tip is formed. ing. Therefore, similarly to the curved part 721 of the lot part 72, when the cup-shaped pressure-receiving thin film 71 is also subjected to the pressure of the fluid to be detected, the stress can be dispersed throughout the curved part 731. Therefore, the pressure resistance of the cup-shaped pressure-receiving thin film 71 can be further improved. In addition, by combining with the curved portion 721 of the lot portion 72, the pressure resistance is further enhanced and the pressure resistance is further improved, so that the life of the cup-shaped pressure receiving thin film 71 can be extended.

[0073] The cup-shaped pressure-receiving thin film 71, the lot portion 72, and the protruding portion 73 are formed as a body. Therefore, the number of parts can be reduced, and the productivity can be improved. Also, compared to a case where the cup-shaped pressure receiving thin film 71 and the lot portion 72 and the protruding portion 73 are bonded and manufactured as separate members, the lot portion 72 and the protruding portion 73 can be separated from the cup-shaped pressure receiving thin film 71 by integrally forming. There is no. For this reason, it is possible to prevent the pressure resistance of the cup-shaped pressure-receiving thin film 71 from deteriorating due to the peeling of the lot portion 72 and the protruding portion 73, and to maintain good pressure resistance.

[0074] Further, the cup-shaped pressure-receiving thin film 71 is fixed by fixing the fixing protrusion 713A to the tapered fixing groove 110D. Therefore, the sealing degree of the cup-shaped pressure-receiving thin film 71 is improved, and the sealing property can be further improved because the cup-shaped pressure-receiving thin film 71 is sandwiched between the upper case 110A and the lower case 110B via the O-ring 80.

Further, since the cup-shaped pressure-receiving thin film 71 is directly attached to the first case 11, the annular member 32 used in the first embodiment is unnecessary, and the configuration can be simplified. Further, by removing the lower case 110B, the cup-shaped pressure-receiving thin film 71 can be easily taken out, so that the maintenance property can be improved.

[Other Embodiments]

It should be noted that the present invention is not limited to the above-described embodiment, and includes modifications and improvements as long as the object of the present invention can be achieved.

For example, in the first and second embodiments, between the pressure receiving portion 30 and the first case 11 Although the configuration in which the annular seal member is provided and closely attached is shown, the configuration is not limited to this. For example, figure

As shown in FIG. 6, an annular projection 10A1 is formed in the opening 10A of the first case 11 along the outer periphery of the thin film layer 31 so as to project annularly to the pressure receiving section 30 side. Then, the pressure receiving portion 30 and the pressure sensor element 20 are press-fitted between the annular protrusion 10A1 and the pedestal portion 13. Even with such a configuration, the pressure receiving section 30 and the first case 11 can be kept in close contact with each other to keep tightness. Further, since the sealing member 113 can be omitted, the number of parts can be reduced.

Further, in the first embodiment, as shown in FIG. 7, the configuration may be such that the thin film layer 31 is directly attached to the first case 11. Further, as shown in FIG. 8, the thin film layer 31 and the first case 11 may be integrally formed. With such a configuration, separation of the thin film layer 31 from the first case 11 can be reliably prevented, and the number of components can be reduced because the seal member 113 is not required.

Further, when the thin film layer 31 is directly attached and fixed to the first case 11 or is integrally formed with the first case, the configuration may be such that the annular member 32 is not provided. In this case, a part of the first case functions as a holding member, and forms a holding space 34 between the thin film layer 31 and the diaphragm 22.

Further, in the above-described embodiment, the pressure receiving portion 30 may be configured such that one pressure receiving portion 30 is provided on the opening 10A side of the pressure sensor element 20 as shown in FIG. In FIG. 9, a first pressure receiving portion 30A is provided on the opening 10A side of the pressure sensor element 20, and a second pressure receiving portion 30B is provided on the opening 10A side. By providing a plurality of pressure receiving portions in this manner, permeation of corrosive gas components of the test fluid can be more reliably suppressed, and corrosion of the diaphragm 22 can be more reliably prevented.

Further, as described above, a pump may be connected to the communication hole 111 so that the holding space 34 can be efficiently ventilated.

[0082] In the second embodiment, the arcs of the curved portion 721 of the lot portion 72 and the curved portion 731 of the protruding portion are described as being formed in an arc shape having a predetermined diameter. Not. That is, the curved portions 721 and 731 may be formed in a curved shape without drawing an arc shape. In the case of a curved shape, similarly to the second embodiment, the cup-shaped pressure-receiving thin film 71 When the is displaced, the pressure can be dispersed to the curved portions 721 and 731, and the pressure resistance can be improved.

Further, the configuration may be such that the cup-shaped pressure-receiving thin film 71 used in the second embodiment is attached to the annular member 32 used in the first embodiment. In this case, as shown in FIG. 10, the annular member 32 is fixed to the outer peripheral portion of the cylindrical portion 712 of the cup-shaped pressure-receiving thin film 71 by, for example, fusion bonding. In such a configuration, the thin-film fixing portion 713 of the cup-shaped pressure-receiving thin film 71 in the second embodiment is unnecessary, and the configuration of the cup-shaped pressure-receiving thin film 71 is simplified. Therefore, the productivity of the cup-shaped pressure-receiving thin film 71 can be improved.

In the first and second embodiments, the force using the capacitance type pressure sensor element 20 as the detection unit is not limited to this. For example, a resistance strain gauge type or the like may be used. For example, a configuration shown in FIGS. 11 and 12 may be used. In FIGS. 11 and 12, the pressure sensor module 2A is provided with a pressure detecting section 60 on the side opposite to the pressure receiving section 30 of the diaphragm 22 via a cylindrical bonding glass 23. The pressure detecting section 60 includes a detecting section main body 61 fixed to the bonding glass 23, and a connecting section 62 extending from the detecting section main body 61 to the diaphragm 22 side and transmitting the displacement of the diaphragm 22 to the detecting section main body 61. Have.

The detection unit main body 61 is formed such that one end is adhered and fixed to the bonded glass 23 and the other end is extended toward the axis of the bonded glass 23. Further, the detection unit main body 61 is formed of a material which is elastically deformable, and when the displacement of the diaphragm 22 is transmitted by the connecting portion 62, the detection unit main body 61 is elastically deformed by the amount of the displacement. An elasticity retaining hole 611 is formed substantially at the center of the detection section main body 61. The elasticity retaining holes 611 buffer the displacement of the diaphragm 22 transmitted by the connecting portion 62. A strain gauge 63 as a strain detecting unit is provided on the surface of the detecting unit main body 61 on the side opposite to the diaphragm 22. This strain gauge 63 detects the amount of deformation when the detecting section main body 61 is elastically deformed. Then, the detected deformation amount is converted into an electric signal and output to a circuit board (not shown). The circuit board recognizes the amount of strain of the detecting section main body 61 from the input electric signal, and obtains the amount of displacement of the diaphragm 22 and the pressure of the fluid to be detected by arithmetic processing.

In addition, the connecting portion 62 has a distal end portion fixed to substantially the center of the diaphragm 22, and Is transmitted to the detecting section main body 61. Therefore, for example, even when the diaphragm 22 is displaced toward the pressure receiving unit 30 when the pressure of the fluid to be detected is a negative pressure, the displacement of the diaphragm 22 can be accurately transmitted to the detection unit main body 61.

[0086] Even in such a configuration, the displacement of the diaphragm 22 can be reliably transmitted to the main body of the detection unit by the connecting portion 62, so that the pressure sensor module 2A can detect the pressure of the fluid to be detected well. Can be.

[0087] Further, a configuration in which a strain gauge is directly attached to the diaphragm may be adopted! In this case, the strain amount due to the displacement of the diaphragm can be directly detected by the strain gauge. Therefore, good detection accuracy can be obtained. Further, since the configuration is simplified, the number of parts can be reduced, and the production cost can be reduced.

[0088] In addition, specific structures and procedures for implementing the present invention can be appropriately changed to other structures or the like as long as the object of the present invention can be achieved.

Industrial applicability

The present invention can be used for a pressure sensor module that detects the pressure of a fluid to be detected, and a pressure detection device.

Claims

The scope of the claims

[1] a thin diaphragm that can be displaced by the pressure of the fluid to be detected,

A detection unit that is disposed on the diaphragm and detects displacement of the diaphragm;

A pressure sensor module comprising:

The diaphragm is disposed so as to face a surface of the diaphragm opposite to the surface on the detection portion side, and is provided via a holding space formed by a holding member, and is displaced by the pressure of the fluid to be detected. Possible thin film layers,

A displacement transmitting unit that transmits the displacement of the thin film layer to the diaphragm;

A vent that communicates the holding space and the external space,

A pressure sensor module comprising:

[2] In the pressure sensor module according to claim 1,

The holding member is an annular member formed on the outer periphery of the diaphragm and the thin film layer.

A pressure sensor module characterized by the above.

[3] The pressure sensor module according to claim 2,

A plurality of the ventilation holes are formed in the annular member.

A pressure sensor module characterized by the above.

[4] In the pressure sensor module according to any one of claims 1 to 3, the displacement transmitting portion is provided substantially on a central axis of the holding space.

A pressure sensor module characterized by the above.

[5] The pressure sensor module according to any one of claims 1 and 4, wherein the displacement transmitting section is fixed to both the diaphragm and the thin film layer. Pressure sensor module.

[6] In the pressure sensor module according to claim 1,

The thin film layer is formed in a substantially cup shape having a bottom portion facing the diaphragm, and a tubular portion extending from an outer peripheral portion of the bottom portion to a side opposite to the diaphragm. Outer peripheral end is fixed to the holding member A pressure sensor module characterized by the above.

[7] The pressure sensor module according to claim 6,

The displacement transmitting portion is formed so as to protrude toward the diaphragm at a substantially central position of the bottom portion and to be curved toward a tip of the displacement transmitting portion at a surface force of the bottom portion.

A pressure sensor module characterized by the above.

[8] The pressure sensor module according to claim 7,

On the side of the bottom surface opposite to the side on which the displacement transmitting portion is provided, there is provided a protruding portion formed so as to protrude in a state of being curved toward the surface force of the bottom surface.

A pressure module characterized by the following.

[9] The pressure sensor module according to claim 8,

The pressure sensor module, wherein the thin film layer, the displacement transmitting portion, and the protruding portion are integrally formed.

[10] The pressure sensor module according to any one of claims 1 to 9, wherein the thin film layer, the holding member, and the displacement transmitting unit are integrally formed. Pressure sensor module.

[11] The pressure sensor module according to any one of claims 1 and 10, wherein the thin film layer is made of a fluorine resin.

A pressure sensor module characterized by the above.

[12] The pressure sensor module according to any one of claims 1 to 11, wherein a pedestal portion is provided so as to face a side surface of the detection portion of the diaphragm,

The detection unit has a capacitor formed by a pair of electrodes provided on a side surface of the detection unit of the diaphragm and a surface of the pedestal unit facing the diaphragm.

A pressure sensor module characterized by the above.

[13] The pressure sensor module according to any one of claims 1 to 12, wherein the detecting unit is a strain detecting unit that detects a strain due to a displacement of the diaphragm.

A pressure sensor module characterized by the above.

[14] The pressure sensor module according to claim 13,

The strain detecting unit is disposed at a predetermined interval from the diaphragm, and is provided on an elastically deformable detecting unit main body connected to the diaphragm by a connecting unit.

A pressure sensor module characterized by the above.

[15] The pressure sensor module according to claim 14,

The strain detector is disposed in contact with the diaphragm.

A pressure sensor module characterized by the above.

[16] The pressure sensor module according to any one of claims 1 and 15, wherein a thin film is attached to the surface of the diaphragm on the thin film layer side.

A pressure sensor module characterized by the above.

[17] The pressure sensor module according to any one of claims 1 to 16,

A case that houses the pressure sensor module therein and has an opening that opens so that a side surface of the thin film layer opposite to the diaphragm faces.

A pressure detecting device comprising:

[18] The pressure detecting device according to claim 17,

The case includes the holding member in a part thereof and fixes a peripheral portion of the thin film layer to form a holding space between the diaphragm and the thin film layer.

A pressure detector characterized by the above-mentioned.

[19] The pressure detecting device according to claim 18,

The case includes an upper case portion disposed on the diaphragm side of the thin film layer, and a lower case portion disposed on the opposite side of the thin film layer from the diaphragm,

The pressure detecting device, wherein the thin film layer is sandwiched and fixed between the upper case portion and the lower case portion.

[20] The pressure detecting device according to claim 19,

At least one of the upper case portion and the lower case portion has a fixing groove at at least a part of a position where the thin film layer is fixed,

The thin film layer has a fixing protrusion fitted on the fixing groove on an outer peripheral portion, and is fixed by being sandwiched between the upper case and the lower case in a state where the fixing protrusion is fitted into the fixing groove. Be done

A pressure detector characterized by the above-mentioned.